Battery cover mold



Oct. 6, 19 42. BRUNER 2,297,741

BATTERY cbvsn MOLD Filed Sept. 21, 1936 6 Sheets-Sheet 1 Def. 6, 19 42. BRQNER 2,297,741

BATTERY COVER MOLD Filed Sept. 21, 1956 6 Sheets-Sheet 2 Oct. 6, 1942, R. A. BRUNER BATTERY COVER MOLD Filed Sept. 21, 1936 6 Sheets-Sheet 5 In 7 7/1 Z w/u im a w Oct. 6, 1942. R. A. BRUNER BATTERY COVER MOLD a Sheets-Sheet e Filed Sept. 21, 1936 f I fl l fl i m Patented Oct. 6,. 1942 PATENT OFFICE 2,297,741 BATTERY oovnn MOLD Ray A. Bruner, Muncie, 1nd,, assignor to General Motors Corporation, Detroit, Mich a corpora tion of Delaware Application September 23 Claims.

This invention relates to molding presses and more particularly to a press for molding articles having a threaded portion, such as covers fo storage batteries.

It is the present day practice in molding battery covers to place the core, which forms the conventional threaded filler hole of a cover, into the cavity of the cover mold in such manner that the core remains in threaded engagement with the cover and is removed together with the latter from the mold, or the core is unscrewed from the cover and withdrawn from the mold cavity prior to the ejectmentof the cover therefrom. Either practice slows down production and, hence, increases the cost of making battery covers.

It is the primary aim and object of the present invention to provide a molding press for battery covers in which the threaded core is permanently-mounted in the mold and is unscrewed from a molded cover in response to the opening of the mold.

It is another object of the present invention to make provision in the molding press for ejecting a cover from the mold while the core is un:

.screwed from said cover.

These and other objects are accomplished by rotatably mounting an axially immovable, threaded core in one of a pair of cooperating molds, and by providing mechanism responsive to the opening of the molds for rotating the core to unscrew it from a molded cover. A manually operable device is further provided for ejecting a cover from the mold at substantially the rate with which the cover and core separate when the latter is unscrewed from the cover, thus preventing the core from functioning as an ejector which would strip the molded thread and cause the cover to become buckled.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings;

Fig. 1 is a front elevation of a molding press embodying the present invention.

Fig. 2 is an enlarged section taken on the line '22 of Fig. 1. 1

Fig. 3 is afragmentary section taken on the line 33 of Fig. 2.

Figs. 4 and 5 are fragmentary sections similar to Fig. 3, showing certain elements in different positions of operation, however,

21, 1936, Serial No. 101,704

Fig. 6 is a fragmentary section taken on the line 6-6 of Fig. 2.

Fig. 'l' is a fragmentary section taken on the line 1-1 of Fig. 6.

Fig. 8 is a fragmentary section taken on the line 88 of Fig. 2.

Figs. 9 to 13 inclusive, are fragmentary sections of a certain operating mechanism of the press in different positions of operation. More particularly, Fig. 1311s an enlarged fragmentary section taken on the line i3- i3 of Fig. 1.

Fig. 14 is a fragmentary section and part plan View of certain mechanism of the press.

Fig.'15 is a fragmentary, partly sectioned elevation of the mechanism illustrated in Fig. 14, and is viewed in the direction of arrow i5 in Fig. 2.

Fig. 16 is an enlarged fragmentary section taken on the line I6--l6 of Fig. 14.

Fig. 17 is an enlarged section of a detail, and is taken on the line ||Il of Fig. 2.

Referring to the drawings and. more particularly to Fig. 1, the instant press comprises a main structure of the press. Projecting vertically from this base are parallel posts 22, preferably four, on which a head 24 is mounted. Movablevertically between base 20 and head 24 is a carrier 26, having lugs 28 which are guided by the 30 posts 22 (see Fig. 2). Aram 30 cooperates with the main cylinder or base 20 and is provided with lugs 32 which are also guided by the posts 22 for vertical movement. Mounted on top of the head 24 are two opposite cylinders 34, receiving 35 plungers 36, the rods 38 of which are secured to opposite lugs 39 of the ram 30. One end 40 of each cylinder 34 is in permanent communication with any suitable supply of fluid under substantially constant pressure, wherefore the plungers 40 36 normally urge the ram 30 into the lowermost position shown in Fig. 1. The main cylinder 20 may either be connected with any suitable supply of fluid pressure, or vented, by a manually operated valve of any suitable make (not shown). Since the end face of the ram 3llwhich is exposed to the fluid pressure in the main cylinder 20 has a greater area than the fluid exposed end faces 42 of both plungers 36 and the pressure of the fluid. supply for the main cylinder 20 is higher than the pressure of the fluid for the cylinders 34, it can be readily understood that admission of fluid pressure into the. main .cylinder 20 results in movement of the ram 30 in the direction of arrow 44 in Fig. 1 against the 5 tendency of the plungers 36 to force the ram .determined by the racks 58 when resting on'the head 24 as shown in Fig. 1.

The illustrated press has two pairs 68 and 82 of cooperating molds 84, 86 each. Both pairs of molds are exactly identical, the upper molds 84 of each pair being mounted on the head 24- and the lower side of the carrier 26, respectively,

- while the lower mold B6 of each pair is mounted on the upper side of the carrier 28 and the ram 30, respectively. The shape of the mold cavities is best illustrated in Figs. 2 and 3 wherein it will be noticed that a pair of cooperating molds comprises two different sets of cavities 88 and 69 for two slightly difierent battery covers. The vertical outerrows of cavities 68 in Fig. 2 serve for the molding-of end covers through which the battery terminals extend. More particularly, the battery terminals are to extend through. acidresisting lead bushings I8 which are molded right in the covers as will be more fully described hereafter. It will also be noticed from Fig. 2 that the terminal receiving bushings I8 are located on the longitudinal center axis of the cover cavities 88 while the remaining bushings II, to be also molded in the covers, are located eccentrically of said axis. These latter bushings II are to receive the posts of conventional plate straps which serve for interconnection of the various cells of storage batteries through suitable connectors. Each one of the covers molded in the instant press is furthermore provided with a filler hole which is normally sealed by a threaded plug. The core which forms the threaded filler hole of each cover is indicated by the reference numeral I2. The mold Y illustrated in Fig. 2 is typical for molding covers for storage batteries having three cells. It appears from Fig. 3 that the terminal bushings III are located at a level different from that of the remaining bushings II. Each bushing I8 and II is embedded in a boss which is formed by recessedportions I8 of each cover cavity 88 and 68, and the threaded filler hole of each cover is provided in a boss which is formed by the recessed portion I6 of each cover cavity. The cover cavities .88, 89 are further provided with suitable recesses 88 to form ribs between the bosses of each cover.

The bushings I8 and" animated in annular recesses 8I of e ch cover cavity 68, 88. These recesses are partly formed by reciprocable plungers 82, the ste 84 of which may be moved into and out of he bushings. The plungers 82 are received in annular recesses 88 of the lower molds 88. Manually operable means for simultaneously reciprocating the plungers 82 of a lower mold 88 into and out of the bushings I8 and II will be described later. It may be stated in advance that the stems 84 of the plungers82 serve not only to reenforce the bushings against collapse under the molding pressure, but also to assist in ejecting the molded covers from the mold cavities. The threaded cores I2 are rotatably mounted in the lower molds 86 and carry bevel gears 88 which project into parallel grooves 98 of said lower molds.

Before starting an operation of the press, the

operator inserts bushings I8 and II into the recesses 8| of both lower, uncharged molds 88 while the press is in the open position shown in Fig. 1. In so doing, the operator manipulates all plungers 82 of ,each lower mold 66 into the uppermost position shown in Fig. 3, so that the stems 84 project completely into the inserted bushings. Since these bushings fit rather tightly over the stems 84, the operator usually hammers the bushings substantially into the position shown in Fig. 3. The operator next closes the molds by manipulating the earlier described valve to admit fluid pressure to the main cylinder 28. The lower pair 62 of molds will first close during the ascent of the ram, while the upper pair 68 of molds will close upon continued ascent of the lower pair 62 of closed molds. The closing molds will force such bushings in place which have not been completely positioned by the operator. The molds are then reopened upon manipulation of the previously mentioned control valve into position to vent the main cylinder 28, and the operator deposits a strip of uncured rubber or other molding material in each cavity 68, 69 of the lower molds 86. The molds, after having been thus charged, are again closed and remain closed until the molded covers are vulcanized, the necessary heat being furnished from steam jackets (not shown) in all molds. After a, predetermined lapse of time the operator opens the molds for removal of the molded covers. During such opening of the molds, the covers are gradually ejected from the lower molds 86 as the threaded cores I2 are unscrewed from the filler holes of the covers in a manner to be described hereafter. The counter-weight 58, while designed to relieve the ram 38 from lifting the full weight of the carrier 26, is of less weight than said carrier so as not to interfere with the opening of the upper pair 88 of molds 64, 86 under the gravity ofthe carrier 26 when the ram 38 descends towards its lowermost position in Fig. 1. Suitable guides (not shown) prevent lateral escape of the counter-weight 58 from between the gears 52.

Referring more particularly to Figs. 2 to 'I inclusive, and 14 to 16 inclusive, the lower mold 68 of each pair of molds is provided with grooves I88 which extend parallel to the earlier mentioned grooves 98 and pass centrally through the vertically aligned recesses 88 as viewed in Fig.2. Pivotally mounted at I82 in these grooves I88 are bell-crank levers I84, one for each plunger 82. 'One end of each lever I84 is roller-shaped and fits into a slot I85 of a plunger 82, while the other end of each lever I84 is provided with a boss I88 (see Fig. 7') The lower mold 880i each pair of molds is provided with another series of grooves H8 which extend parallel to the earlier described grooves 88 and I88. Movable in the grooves 8 are bars II2 which are abutted by the bosses I88 of the levers I84 in the manner disclosed in Fig. '7. These bosses I88 .extend through suitable recesses H4 in the partition II5 between adjacent grooves I88 and H8. A pin Illi connects each lever I84 .to a bar II2. As more particularly shown in Fig. 14, each of the bars 2 of a pair of molds is connected to a crank arm H8 of a crank shaft I28 which is mounted in suitable bearings I22, I24 and I28 on the lower mold of said pair. Mounted on the crank shaft I28 intermediate two crank arms thereof is a bevel gear segment I28 which is in permanent mesh with a similar segment I38,

keyed to a stub shaft I32 which is rotatably mounted in a bearing bracket I34 on said lower mold 66, and more particularly at the rear of the press as illustrated in Fig. 1. Also secured to the stub shaft I32 is' a rocker arm I36 (see Fig.

) which may be manipulated by the operator to cause reciprocation of the plungers 82 through intermediation of the bevel gears I30 and I28, crankshaft I20, bars II2, pins H6 and levers I04, as can be readily understood. Since the various bushings 101I are alternately differently spaced from the adjacent end faces I38 and I40 of the lower mold 66 as appears from Fig. 2, the'shortest distance d between a bushing and an end face of the lower mold is too small to accommodate alever I04, the variousrows of levers I04 that a ratchet mechanism is provided in each of the bevel gears I58 which is so operative as to prevent rotation of the cores 12 when the molds for plungers 82 which are equally situated with I respect to the cover cavities 68 are so disposed in the grooves I00 that none of them is located in a groove I00 within the distance d from the their connection through the bars II2 to diametrically opposite crank portions of the crankshaft I20, since it is imperative that n plungers 82 be moved in unison and in the same. direction. The coordination between the crankshaft.

I and thelevers I 04 is such that approximately 90 rotation of the crank arm I36 results in movement of the plungers 82 from the uppermost position in Fig. 3 to a lowermost position in ,which the stems 84 of the plungers are flush with the bottom surfaces I42 of the annular recesses 8|. Of course, each pair 60, 62 of molds is provided with a crank shaft I20 and actuating crank arm I36 for reciprocating the plungers in both lower molds 66 of the two pairs.

As best shown in Figs. 2 and 8, the bevel gears 88 of each row of cores 12 are in permanent mesh with other bevel gears I50 which are mounted on shafts I52, rotatably mounted in end 'plates' I54 on the lower molds 66. As more particularly shown in Figs. 1 and 2, one end of the shafts I52 of each pair of molds carries-a bevel gear I56 which is in mesh with a larger bevel gear I58, mounted on a shaft I60 which is journaled in suitable bearing brackets I62 on the carrier 26 and ram 30, respectively. Both shafts I60 carry furthermore gears I64 which are in mesh with larger gears I66, mounted on suitably journaled stub shafts I68 on the carrier 26 and ram 30, respectively. Also mounted on the stub shafts I68 are other gears I10 which mesh with racks I12 and I13, respectively, both racks being.

slidably mounted in a dove-tail guide I14 which extends from the main cylinder 20 to the head and is secured to both as best shown in Fig. 1.

During movement of the ram 30 and carrier 26 from the position shown in Fig. 1 to that shown in Fig 9 in which the molds are closed, the racks I12, I13 travel with the ram and carrier since the static friction in the drive from the gears I10 to the threaded cores 12 considerably exceeds the static friction between the racks and their guide I14. Thus during closing of thethe ascending ram and carrier would be ro-' tated by the stopped racks I12, I13 and cause rotation of the cores 12. were it not for the fact are being closed. Rotation of the cores 12 during closing of the molds would result in dislocation of the overlying strips of rubber which have been positioned longitudinally of the cover cavities 68---69. These ratchet mechanisms are alike for each bevel gear I58 and one of these mechanisms is shown in detail in Figs. 2 and 1'1. It appears from these figures that a hub I18 of each bevel gear I58 is keyed to the shaft I60 of each pair of molds and that the bevel gear I58 is journaled on said hub. Endwise movement of the bevel gear I58 on shaft L60 is prevented by a collar I and a' ratchet disc I82, both being secured to the hub I18 The bevel gear I58 is provided with an annular recess I84 in which two diametrically opposite pawls I86 are pivoted at I88. Suitably tensioned springs I90 normally force the pawls I86 into engagement with the ratchet disc I82. The ratchet disc I82 and the pawls I86 are so associated that the driving ratchet disc rotates idly past-the pawls in counterclockwise direction as viewed in Fig. 1'1 when the molds are closed. The cores 12 are thus prevented from rotating while the molds are being closed.

Reference is now had to Figs. 9 to 13 inclusive, which illustrate progressive stages in the opening ofthe molds. Fig. 9 shows the molds in closed position. During the slight retraction of the ram 30 from the position shown in Fig. 9 to that shown in Fig. 10, the upper rack I13 descends with the carrier 26 until said rack engages the stop I 16. molds are, therefore, not rotated during such retraction. The upper mold 84 of said pair is now appreciably retracted from its companion mold 66 and from the molded covers therein which stickto said companion mold due to their threaded engagement with the cores 12. Unscrewing of the molded covers from the companion mold 66 may therefore safely start when said mold arrives in the position shown in Fig. 10. Continued descent of the ram 30 from the position in Fig. 10 causesgear I10 of said companion mold 66 to be rotated by the stopped rack I 13 in a direction in which the cores 12 are rotated to unscrew from the filler holes of the molded covers in said companion mold 66, substantially as illus'-' trated in Fig. 4. The upper pair 60 of molds separate until the carrier 26 reaches its lowermost position in Figs. 1 and 11, at which time the cores 12 in said companion mold 66 are just unscrewed from the molded covers. This is accomplished by selection of proper ratios between the various gears which transmit the rotary motion of the gear I10 to the cores 12. The molded covers have a tendency to stick in the comers of their mold cavities, thereforeit is imperative that the covers are uniformly ejected from the companion mold 66 at substantially the rate with which the covers and cores 12 separate when the latter are unscrewed from the covers in order to prevent the core from functioning as an ejector which would strip the molded threads and cause the covers to become buckled. This'is done by the operator who manipulates the earlier described crank arm I 36 on the upper mold 66 while the cores 12 unscrew from the covers, i. e. during separation ofthe upper pair 60 of molds from the position in Fig. 10 to that in Fig. 11. The operator first withdraws the plunger stems 84 almost completely from the bushings substantially when The .cores 12 of the upper pair 60 of the molds are open to the extent illustrated in Fig. 10. As soon as the cores 12 start to unscrew from the molded covers, the operator who becomes aware of this fact by the growing gap between the separating molds imparts short and rapid oscillations to the crank arm I36, shifting the range of oscillations thereby gradually in the direction in which the reciprocating plunger stems 84 advance into the bushings. The operator knows by experience how fast he can advance the reciprocating stems 84 into the bushings so as to prevent the resistance offered, by the bushings to the advancing stems 84 exceeding an amount which results in buckling of the covers and/or stripping of the threads in the covers. The stems 84 of the plungers 82 are slightly tapered to'facilitate their repeated retraction in the bushings during ejection of the covers. The

. cover-ejecting friction, static and sliding, between the repeatedly advancing stems 8 4 and the bushings is not counteracted by the unscrewing cores as is the friction between the retracting stems 84 and the bushings. This explains why the repeated reciprocations of the stems 84 cause gradual ejection of the molded covers from the mold. The bushings which are made of lead to :resist acid become heated during the vulcanization of the covers and therefore shrink during the opening of the molds. The ,amount of shrinkage of thebushings is, however, practically negligible and does not interfere with the ejection of the covers from their cavities in the aforementioned manner. comparatively short-and rapidly repeated reciprocations will never lead to such ramming of the stems 84 into the bushings that the stems will either stick to the bushings or that such a. force has to be exerted which might cause buckling of the covers. Furthermore, withdrawal of the stems 84 from the bushings is facilitated by slightly tapering these stems. To further facilitate the removal of the molded covers from their cavities it is preferable to mount the cores 12 as well as the plungers 82 in that mold from which removal of the molded covers takes the least amount of ejecting force. It will be noticed from Fig. 3 that in the absence of the threaded cores 12 and the plunger 82, the molded covers would stick to the upper mold 64 upon separation of both molds, since the cavities of the upper mold are more irregular than the com- 1 and .13 results in opening of the lower pair 62 of molds. After the lower pair of molds becomes separated to the extent shown in Fig. 12,, the cores 12 start to unscrew whereupon the operator manipulates the crank arm I36 of the lower pair of molds for gradual ejection of the covers in the same manner as previously described with respect to the upper pair 60 of molds. More particularly, the rack I12 engages a stop 200 on the guide I14 after separation of the lower pair of molds 60 to the extent shownin Fig. 12. Thus, by comparing Figs. and 12, it can be understood that the cores in both pairs of molds start to unscrew after the same separation between the cooperating molds thereof.

It is of course, imperative for a successful operation of the cores that the gears I10 are in permanent mesh with the racks I12 and I13, respectively. Consequently, rack I12 has to be in ;mesh with its gear I10 in any of the illustrated positions of the lower mold 66 of the lower pair in Figs. 9 to 13, inclusive. It is a further requirement that the rack moves with said lower-mold during movement from the position shown in Fig. 9 to that shown in Fig. 12, and vice versa, so as to prevent premature rotation of the cores in said lower mold while the pair 62 of molds is still closed. It is also a requirement that the rack I12 is stationary during descent of said lower mold from the position in Fig. 12 to that in Fig. 13 so as properly to unscrew the cores 12 from the covers. All these requirements necessitate the short rack I12 illustrated in the drawings. To prevent descent of this rack I12 under its own gravity from the position in Fig. 10 into engagement with the stop 200 and thereby demesh from its gear I10, a hook 202 is secured to the ram 30 which is so positioned as to engage the rack I12 and carry it upward with the ram from the position shown in Fig. 12 in which rack I12 is equally as coordinated to its gear 'Illl as rack I13 is coordinated to its gear I10 in the position shown in Fig. 10. The hook 202 is furthermore so positioned as to be able to pass the stop 200.

It is obvious from the foregoing that the unscrewing of the cores from the molded covers in both pairs of molds is responsive to the opening of the molds and that both pairs of molds are closed and opened by a single ram.

This invention is not limited to the combination between the rotary threaded cores and the cover ejecting means. Emphasis is laid on certain advantages which are secured by the cover ejecting means in the absence of any threaded cores. In molding battery covers without the threaded filler hole, for instance, the described cover ejecting means accomplishes three important functions, to wit, reinforcing the molded-in bushings against collapse under the molding pressure, ejecting a molded cover from the mold, and withdrawing the ejecting means (stems B4 of plungers 82) from the molded-in bushings as the cover is gradually ejected from the mold. It can be understood that upon short reciprocations of the plungers 82, the molded covers will be gradually forced from the mold rather than into the mold, because the least resistance against movement of the covers by frictional driving engagement with the reciprocating plunger stems 84 is offered in the direction in which the covers leave the mold. The slightly tapered surfaces of any mold, designed to facilitate removal of a molded article therefrom are a contributory factor in the successful operation of the above applied ejeoting plungers 82, in that the return of a partly ejected cover into the mold meets with an increasing binding force on the tapered cavity walls of the mold which is not overcome by the friction between the-molded-in bushings and the receding plungers 82.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

1 What is claimed is as follows: 1. In a molding press, the combination of cooperating molds deflning a cavity; a threaded core rotatably mounted in one of the molds; and

means to assist in the ejection of a molded article from said one mold as the core is rotated to unscrew from the threaded hole in the article.

2. In a molding press, the combination of cooperating molds deflning a cavity; a threaded .core rotatably mounted in one of the molds;

means responsive to opening of the molds for rotating the core to unscrew from the threaded hole of a molded article; and means to assist in the ejection of the molded article from said one moldas the core unscrews from the article.

3 In a molding press, the combination of cooperating-molds defining a cavity; a threaded core rotatably mounted in one of the molds; means for rotating the core upon separation of the molds; and a pin reciprocable in said one mold and into the cavity and adapted to fit into a bushing in the cavityduring molding and to assist in the ejection of the molded article from said one mold while the core is rotating, the pin being gradually withdrawn from the molded-in bushing by short reciprocations; and means for reciprocating the pin.

I from the molded-in bushing by short reciprocations.

5. In a molding press, the combination of aligned pairs of cooperating molds defining cavities, one mold of one pair being stationary and all other molds being movable; a single ram for opening and closing the pairs of molds successively; threaded cores rotatably mounted in the cavities of one mold of each pair; means for each pair of molds and responsive to the opening thereof for rotating the cores to unscrew'from the threaded holes of the molded articles; and manually operable means for each pair of molds to assist in the ejection of the molded articles therefrom.

6. In a molding press, the combination of aligned pairs of cooperating molds defining cavities, one mold of one pair being stationary and all other molds being movable; a single ram for opening all pairs of molds successively; threaded cores rotatably mounted in the cavities ofone mold of each pair; pins reciprocable in said one mold of each pair and into the cavities thereof and adapted to fit into bushings in said cavities during molding and to assist in the ejection of the molded articles from the molds as the pins are gradually withdrawn from the molded-in bushings by short reciprocations; means fo each pair of molds and responsive to opening to the molds thereof for rotating the cores to unscrew from the threaded holes of the molded articles; and manually ,operable means for each pair of molds to reciprocate the pins thereof simultaneously and in the same direction.

7. In a molding press, the combination of separable cooperating molds defining a cavity; a threaded core rotatably mounted in one of the molds; and means responsive to opening of th molds for rotating the core, said means including a gear on said one mold and a meshing slidable rack, and mechanism to cause relative movement between gear and rack while the molds 5. In a molding press, the combination of separable cooperating molds defining a cavity; a threaded core rotatably mounted in a movable mold; and means responsive to opening of the molds for rotating the core, said means including a gear on said movable mold, a slidabl rack in mesh with said gear, and a stop for the rack,

9. In a molding press, the combination of separable cooperating molds defining a cavity; a threaded core rotatably mounted in a movable mold; and means responsive to movement of said movable mold relative to the other mold for rotating the core, said means including a, train of meshing gears on said movable mold and in driving connection with the core, a slidable rack in mesh with one of said gears, two stops tobe engaged by the rack upon movement in either direction, and an element in the train of gears to transmit rotation in one direction only.

10. In a molding press, the combination of two aligned pairs of cooperating molds defining cavities, one mold of the first pair being stationary and all other molds being movable; a single ram for opening and closing both pairs of molds successively; threaded cores rotatably mounted in one movable mold of each pair; and means responsive to opening of each pair of molds for rotating the cores thereof, said means including a train of meshing gears on each of the core carrying molds and in driving connection with the cores, two slidable racks each meshing with a gear of a train, and mechanisms each causing rotating the cores thereof, said means including a train of meshing gears on each of the core carrying molds and in driving connection with the cores, two slidable racks each meshing with a I gear of a train, stops so located as to be engaged by the racks during relative movement between the molds of their respective pair only, and an element engaging the rack of the second pair of molds and moving it with said pair during the closing of .the first pair of molds so as to prevent demeshing of said rack from its gear.

12. In a molding press, the combination of two aligned pairs of cooperating molds defining cavities, one mold of the first pair'being stationary and all other molds being movable; a single ram for opening and closing both pairs of molds successively; threaded cores rotatably mounted in one movable mold of each pair; and means responsive to opening of each pair of molds for rotating the cores thereof, said means including a train of meshing gears on each of the core carrying molds and in driving connection-with the cores, twoslidable racks each meshing with a gear of a train, stops so located as to be engaged by the racks during relative movement between the molds of their respective pair only, and an element in each train of gears to transmit rotation in one direction only.

13. In a molding press, the combination of two aligned pairs of cooperating molds defining cavities, one mold of the first pair being stationary and all other molds being movable; a single ram for opening and closing both pairs of molds successively; 1 threaded cores rotatably mounted in one movable mold of each pair; and means re-. sponsive to opening of each pair of molds for rotating the cores thereof, said means including.

carrying molds and in driving connection with the cores, two slidable racks each meshing with a'gear of a train, stops so located as to be engaged by the racks during relative movement between the molds of their respective pair only, an element in each train of gears to transmit rotation in one direction only, and another element engaging the rack of the second pair of molds and moving it with said pair during the closing of the first pair of molds so as to pr vent demeshing of said rack from its gear.

14. In a molding press, the combination of a movable and cooperating stationary mold; a threaded core rotatably mounted in the movable mold; meshing gears on the movable mold and in driving connection with the core; a rack slidable in the direction of movement of the movable mold and in mesh with one of the gears; and two stops to be engaged by the rack uponmovement in either direction, the stops being separated a distance slightly less than the preassigned opening and closing stroke of the movable mold, and .the ratio between the gearsbeing such that the core unscrews from the threaded hole of a molded 7 article toward the end of an opening stroke of the movable mold.

15. In a molding-press, the combination of two aligned pairs of cooperating molds defining cavities, one mold of the first pair being stationary and all other molds being movable; a single ram for opening and closing both pairs of molds successively; threaded cores rotatably mounted in one movable mold'of each pair; andmeans responsive to opening of each pair of molds for rotating the cores thereof, said means including a train of meshing gears on each of the core carrying molds and in driving connection with the cores, two slidable racks each meshing with a gear of a train, and mechanisms each causing relative movement between the rack and meshing separate manually operable means for each pair of molds to assist in the ejection of the molded articles therefrom as the cores unscrew from the articles.

16. In a device as described the combination of the male mold section being removable after the forming of the article, means to retain the stem and the threaded insert together with the first mold structure from relativelongitudinal movement in all procedures of the operation and means to rotate the stem and hence the threaded insert to unthread the article and disengage said article from the cavity of the first mold section and from the threaded insert.

17. In an apparatus for forming molded articles, the combination of a first mold member having a plurality of aligned mold cavities, a plurality of stems one Of which extends vertically upwardly in the center of each mold'cavity, each' stem having a threaded maleinsert as its upper end of larger diameterthan the stem and each insert being seated against the bottom of its associated mold cavity to thereby prevent formation of flash or rind longitudinally of the stem,

gear of a pair of molds While the same opens; and 1 means to prevent longitudinal movement between each stem and said first mold member in all of the operations of th apparatus, a complementary top or male mold member adapted to cooperate with said first mold member to form a plurality of molded articles at one operation of the apparatus and to form threaded openings surrounding said inserts, and means for simultaneouslyv rotating. said inserts, said top or male mold being separable from its cooperating mold member to permit removal of the molded articles upon rotaoperating said devices during the rotation of the.

core in order to aid in ejecting the molded article from the mold cavity.

19. In a molding press, th combination of cooperating molds defining a cavity and separable to permit removal of the molded article, a core rotatably mounted in one of the molds and having threads thereon to engage the molded article, means responsive to the separation of the molds for rotating the core to move the molded article away from the surface of the mold in which said core is mounted, a pair of reciprocating pins located in said moldon opposite sides of said core and engaging said molded article, and means for reciprocating said pins during the ro-'- tation of the core in order to aid in ejecting the molded article from the mold cavity.

20. In a molding press, the combination of cooperating mold members defining a cavity and separable to permit removal of a molded article, said cavity being adapted to receive a bushing about which the molded article is formed, r0- tatable means for withdrawing the molded article from the mold, a pin mounted for reciprocatory movement into and out of the bushing during the withdrawal of the molded article from th mold cavity iri order to assist in the ejection of said molded article, and manually operable means for reciprocating the pin in said'bushing as the I molded article is withdrawn and for withdrawing the pin from said bushing.

2-1. In a molding press, the combination of cooperating mold members defining a cavity and separable to permit removal of a molded article,

said cavity being adapted to receive a bushing about which the molded article is formed, rotatable means for withdrawing th molded article from the mold, a pin mounted for reciprocatory movement into and out of the bushing during the withdrawal of the molded article from the mold cavity inorder to assist in the ejection of said molded article, and means operable simultaneously with said rotatable means for reciprocating the pin in said bushing as the molded article is withdrawn and for withdrawing the pin from said bushing.

22. In a molding press, the combination of 00,- operating mold members defining a cavity and separable to permit removal of a molded article, said cavity being adapted to receive a bushing about which the molded article is fcrmed, ro-

tatable means for withdrawing the molded artic e {mm the mold, a pin mounted for reciprocatory movement into and out or the bushing during the withdrawal of the molded article from the mold cavity in order to assist. in the ejection of said molded article, and means for repeatedly reciprocating the pin into and out of said bushingv during the operation of said rotatable means in order to assist in the withdrawal of the molded article from the mold cavity.

23. In a molding press, the combination of 00- operating molds defining a cavity which is adapt ed to receive a plurality of bushings, a threadedcore rotatably mounted in one of the molds andprojecting into the cavity so that the molded arin the withdrawal of the molded article from the mold cavity, said last named means being efiective to move all the pins in the same direction at 'Qne time.

RAY A. BRUNER. 

